Method for making tobacco products



Oct. 5, 1965 H. B. PARMELE ETAL 3,

METHOD FOR MAKING TOBACCO PRODUCTS Original Filed April 5, 1961 mm oM NMNM \N MNuQ s Q &

INVENTORS. HARRIS B. PARMELE,

FREDERICK J. SCHULTZ, CHASE W. LASSITER 8 JIMMY H. BELL BY theirATTORNEYS United States Patent 3,209,763 METHOD FOR MAKING TOBACCOPRGDUCTS Harris B. Parmele, Glen Ridge, N..l., and Frederick J.

Schultz, Chase W. Lassiter, and Jimmy H. Bell, Greensboro, N.C.,assignors to P. Lorillard Company, New York, N.Y., a corporation of NewJersey Original application Apr. 5, 1961, Ser. No. 100,842, now PatentNo. 3,166,078. Divided and this application Nov. 20, 1962, Ser. No.245,343

5 Claims. (Cl. 131-140) This is a division of United States applicationSerial No. 100,842, filed April 5, 1961, now US. Patent No. 3,166,078.

This invention relates to methods for making tobacco products, and hasparticular reference to restoring waste tobacco into usable formespecially adapted for mixture with, or as, chewing tobacco.

It is well known that during the stripping of leaf tobacco inpreparation for its use for cigar wrappers or filler, cigarettes andsmoking tobacco, a substantial quantity of stems and leaf scraps remainsas waste although some of it has been used for making snuff and formixture with chewing and smoking tobacco. In addition there is thetobacco scrap and dust resulting from shipping, handling and othercauses. Inasmuch as this so-called waste is high grade, flavorfultobacco, numerous proposals for its economic use have been made,principally its conversion into the form of synthetic leaf orreconstituted tobacco made by adhesively binding finely ground tobaccoand forming the mixture into sheets, ribbons or the like andsubstituting the same in Whole or in part for natural leaf in cigars,cigarettes, smoking tobacco and other tobacco products.

In addition to the problem of impairment of the tobacco flavor in thesmoke from burning reconstituted tobacco caused by the adhesive bindersused for uniting the fine tobacco particles into a reconstituted sheet,there are economic and other disadvantages resulting from this practice.For example, the commercial use of well-known pa per making techniquesin manufacturing such reconstituted tobacco in sheet or ribbon formrequires 24 hour, 7 day week operation in order to be economicallyfeasible. Also, large volumes of water must be used to form thenecessary screen slurry, with the result that many of the desirableconstituents of the natural tobacco are leached out by and lost in theexcess water that drains from the screen. After forming the rudimentarysheet on the screen, the water remaining therein must be evaporated,either by heat or prolonged air drying, which further removes some ofthe desirable volatile tobacco components, easily lost because of thelarge surface exposure of the fine tobacco particles. After drawing, thereconstituted sheet is relatively brittle and cannot be freely handledwithout loss in subsequent manufacturing operations and the product haslittle Water resistance without disintegrating and hence cannot bedipped in flavoring solutions such as are commonly added to smoking andchewing products.

In accordance with the present invention, reclaimed tobacco fines areunited into a self-sustaining sheet or ribbon Without the use ofsubstantial volumes of water or added heat, costly paper-makingtechniques and machinery, but instead by a simple method and apparatusto form a novel product which is especially adapted as and for mixturewith chewing tobacco.

The invention comprises mixing finely-divided tobacco from any sourcewith a tasteless and odorless thermoplastic resin having a relativelylow softening point, working the mixture under such conditions that thefriction between the tobacco particles and the resin and between eachother generates sufficient heat to soften the resin so that theparticles and resin flow together and may be formed into a sheet, ribbonor the like, which when 3,209,763 Patented Oct. 5, 1965 cooled to removethe heat of friction, results in a homogeneous body which isself-sustaining but sufliciently flexible to be readily handled and usedwithout disintegration for formation into cakes or plugs, small sheetsor flakes, sticks and the like for use as or in admixture with chewingtobacco.

More particularly, the invention comprises grinding to relativelyuniform particle size Waste tobacco such as stems, leaf scraps,particles and dust resulting from leaf stripping, storage, manufactureand handling, then intimately mixing the ground tobacco with awater-insoluble resin, such as the polymeric vinyl ester type,preferably with a suitable plasticizer for the resin, and adding suchsweetening and flavoring materials as may be desired for the finishedproduct. The resin may be in the form of granules or an emulsion orsolution thereof and may be mixed with the plasticizer before admixturewith the tobacco, with the flavoring materials added during thetobacco-resin mixing operation. The resulting dry or substantially drymixture is then worked under pressure by a milling operation between aseries of rollers or by pressure extrusion through an extrusion pressuntil the heat generated by the friction between the resin and thetobacco particles, and between each other, reaches or slight ly exceedsthe softening point of the resin, whereupon the mixture becomes plasticand the particles flow together into a homogeneous mass which, whencooled to remove the auto-generated heat, results in a solid,self-sustaining flexible body of any desired form or shape, such as asheet, ribbon, rod or the like.

Referring to the drawings:

FIGURE 1 illustrates semi-diagrammatically the novel apparatus wherebythe method of this invention may be carried out to produce the productof this invention;

FIG. 2 is a cross-section through the apparatus of FIG. 1 as seen alongthe line 2-2 of FIG. 1, and

FIG. 3 is a semi-diagrammatic section through an extrusion apparatuswhereby the method of this invention may be alternatively performed.

Referring to the drawings, and with particular reference to FIGS. 1 and2, the admixture of at least 60% by weight of dry ground tobacco, at afineness of 8 mesh per square inch or less, from any source, mixed withnot more than 40% by weight of a water-insoluble thermoplastic binder,e.g., a granular polyvinyl acetate resin, is fed by gravity from ahopper 10 to a distributing slot as a layer 11 across a travelling steelbelt 12, driven at slow speed, e.g., 10 feet per minute, by chain 13from motor 14. The belt 12 carries the tobacco-resin mixture, levelledby fixed blade 15 to a thickness of about /8 inch, into the nip of tworollers 16, 17, driven at the same peripheral speed but in oppositedirections by a chain 18 from motor 19 and a sprocket 20 and chain 21from motor 14.

As the tobacco-resin mixture passes along with belt 12 into and betweenthe nip of rollers 16 and 17, which may be knurled to increase thefriction of their surfaces, the mixture is worked by a milling operationin the first stage. This milling operation involves considerableinter-particle mixing and consequent friction between the resin and thetobacco particles and between the resin particles and the tobaccoparticles. This pressure milling or working generates considerablefrictional heat but not enough heat to soften the resin to the adhesionpoint, which in the case of polyvinyl acetate is about 92 C. However,sufficient bonding takes place to effect non-selfsupporting coherence,particularly when the rollers are closely-spaced. To that end, therollers 16, 17 are fixedly but adjustably journalled in frame 26 so asto be spaced apart about 0.003 to 0.01 inch at the nip. Hence, theresin-tobacco layer is gradually compressed from about /a to as littleas 0.003 inch as it enters the nip from between the flaring surfaces ofthe rollers 16, 17. As the result, the autogeneous heat 3 frictionforms'the resin-tobacco mixture into the rudimentary sheet or ribbon S,which, being non-selfsustaining, requires support by the platform 27.

As it emerges from between the rollers 16, 17 the heat softened sheet orribbon S expands to about double the nip thickness, i.e., about 0.006 to0.02. inch, and also tends to stick somewhat to the rollers 16, 17 sothat tangential doctor blades 28 adjustably mounted on frame 26 strip itfrom the surfaces of rollers 16, 17.

The expanded rudimentary sheet is pushed along platform 27 into the nipof a second set of rollers 22 and 23 journalled on frame 26 and alsospaced apart about 0.003 to 0.01 inch at the nip and knurled if desired,driven at the same speed and direction as rollers 16, 17 by respectivechains 18 and 21 meshing with corresponding sprockets 24, 25. Doctorblades 29 engage the surfaces of rollers 22, 23, also being adjustablymounted on the frame 26.

Further milling of the tobacco-resin mixture to secure the requisitehomogeneity and the self-supporting properties may be desired for thesheet or ribbon S, which is at least partially unitarily bonded as itemerges onto platform 30 from between rollers 22, 23. Hence, a third setof milling rollers 31, 32, preferably spaced apart the same distance asare rollers 16, 17 and 22, 23, may be provided and are driven at thesame surface speed as those preceding rollers by the respective chains18 and 21, meshing with corresponding sprockets 33 and 34 fixed totheshafts of rollers 31, 32.

The autogenously heated and bonded sheet or ribbon S emerging frombetween the third set of rollers 31, 32 is stripped therefrom by fixeddoctor blades 35 and, expanding to a thickness of at least about 0.006to 0.02 inch, is supported on platform 36.

Depending on the thermoplastic resin selected and upon the degree ofself-sustaining strength and flexibility desired for the finished sheet,a fourth and even a fifth set of milling rollers may be desired.Considering the fourth set, rollers 37, 38 are preferably spaced apart0.003 to 0.01 inch and driven at the same peripheral speed of precedingrollers 31, 32 by respective chains 18 and 21 as shown in FIG. 1. Theserollers 37, 38 recompress the sheet or ribbon S entering their nip fromplatform 36 and consequently further mill and thus add morefrictiongenerated heat thereto, so that greater strength and flexibilityare added. Accordingly sheet or ribbon S emerges from between rollers37, 38 and doctor blades 39 onto platform 40 in finished form, requiringonly removal of the residual friction heat and that may be simplyaccomplished by cool air jets from header 41 extending over the sheet orribbon S as it is carried from platform 40 onto and by belt 42 drivenfrom chain 21, as shown in FIG. 1.

The finished continuous sheet or ribbon S carried by belt 42 preferablyhas an average thickness of about 0.01 inch and may be severed intoshort lengths S by an intermittently engaging rotating blade 43 drivenfrom motor 19. The severed lengths S are collected in container 44 forformation into cakes, plugs, small sheets or flakes, sliced into narrowstrips or the like, depending on requirements.

Where roller sets additional to the four sets shown in FIG. 1 aredesired or required, it will be understood that they will be driven inthe same way as the preceding roller sets.

The heat of friction for autogenously binding the finelydividedparticles together with a thermoplastic resin such as the polymericvinyl ester type may also be provided by extruding the tobacco-resinmixture under pressure through a progressively contracting tube in aknown manner. However, it is preferred that the extrusion step followsthe milling or working step afforded by at least the first set ofrollers 16, 17 shown in FIG. 1, in order to obtain the desiredhomogeneity of mixing with some bonding provided by the initial heat ofcompression between the rollers. Thus, as shown semi-schematically inFIG. 3, the resin-tobacco sheet or ribbon S" emerging from betweencompression rollers 16, 17', onto platform 45 following doctor blades 46enters the cylinder 47 of the extrusion press to be severed andcompressed by reciprocating piston 48 driven by crank wheel 49. Thepiston 48 forces the severed sheet S into the converging funnel 50,where it is compressed with increasing friction-generated heat, whichsoftens the resin still more to the point where it flows and bonds thetobacco particles together. The highly compressed and hot tobacco-resinmixture emerges from funnel 50 as a homogeneous self-sustaining rod orribbon R, which may be severed into short lengths for admixture withchewing tobacco or used directly as chewing tobacco, depending onrequirements.

As stated, the preferred binder is a resin of the polymeric vinyl estertype such as polyvinyl acetate derived from an acid containing only twocarbon atoms. Resins of this type are preferred because they are notonly waterinsoluble, thus precluding the finished product from becomingsticky or friable in moist atmosphere and enabling treatment by addedflavoring compounds without damage, but also because such resins areodorless and tasteless, thus leaving available the full flavor of thetobacco without impairment of taste by the resin. However, because suchres-ins burn with an odor considered by some to be unpleasant, theproduct of this invention has greatest utility in or as chewing tobaccoswith or without sweetening or flavoring additives such as licorice,fruit extracts, molasses and sugar. The product is not appreciablyattacked by cas-ing solutions or saliva, but will release the includedtobacco and added flavoring materials in the same way and at the samerate as does the highest quality chewing tobacco. Although the productis best adapted for chewing purposes, small quantities thereof may bemixed with smoking pipe or cigarette tobacco without noticeablyaffecting the odor or taste of the latter.

The preferred polymeric vinyl ester resin is polyvinyl acetate,commercially known as Elvacet 81-3300 or Vinac B7 for example, or amixture of polyvinyl acetate and polyethylenevinyl acetate, commerciallyknown as Elvax or Elvax 250, for example. The physical properties offlexibility and toughness imparted by these resins to the finishedproduct may be varied by choosing from the various commercial gradesthereof with respect to molecular weight chain length or degree ofcross-linking and branching. Thus, the higher molecular weight or morecross-linked material gives a tougher, less flexible product, whereas aresin of this type having a low molecular weight gives a more flexibleand less tough product. The resin may be used as an emulsion with water,as a solution with an organic solvent such as ethanol or as a solid inthe form of small beads or powder, all easily and equally usable. Wherea resin solvent such as ethanol is preferred, the solvent evaporatesquickly from the sheet or ribbon S between the compression stages andsuch evaporation is hastened by the heat of compression.

The preferred plasticizer is chosen from that group which has beengovernment-approved for use as food additives, e.g., triacetin, and maybe mixed with the resintobacco mixture before it is fed to the hopper10. Flavoring compounds may be added before or after the hopper 10, asby dusting or spraying the same on initial layer 11.

Typical examples of methods of compounding the ingredients and theresulting products according to the invention are as follows:

Example I Two grams of triacetin were mixed well with 36 grams of awater emulsion of polyvinyl acetate containing 55% solids. Afterthorough mixing, this emulsion was added to 40 grams of powdered cigarleaf tobacco. The resulting mixture was thoroughly blended in a mullertype mixer. Four grams of powdered sugar and 1 gram of powdered licoricewere added and the blending continued for 20 minutes. It should be notedthat the blending time is not critical and can be shortened to a smallfraction of that mentioned here if it is so desired.

After the desired amount of blending the material was dried by suitablemeans, such as by use of a belt drier with infrared heaters, until themoisture content was of the order of to The dried material was thenpassed between several sets of mechanically driven rollers set with aspacing of 0.003 to 0.01 inch. The product emerged from the last rollingas a continuous ribbon with a thickness roughly twice the spacingbetween the last set of rolls.

Example ll Two grams of triacetin were added to 33.4 grams of a 60%solution of polyvinyl acetate in ethanol. This solution was well stirredinto a mixture of 40 grams of cigar tobacco, 4 grams of powdered sugarand 1 gram of powdered licorice. Most of the ethanol was removed fromthis mix-ture by means of a belt drier. The resulting powder was thenfed into a set of rollers with the spacing set as indicated in theprevious example. The material from the first set of rollers was fedinto a second set and so forth until a continuous ribbon was formed. Inthis instance, five sets of rollers were required.

It was not necessary to remove all of the ethanol in the dryingoperation since the remainder was driven off by the heat generated bythe milling action of the rollers. This milling action also achieved thefinal blending of the plasticized resin with the other materials in theproduct.

As was the case in the previous example, the ribbon formed wasapproximately twice the thickness of the space between the rolls used inthe final rolling.

Example Ill Two grams of triacetin were stirred into 20 grams ofpowdered polyvinyl acetate. The resulting moist powder was mixed with 40grams of ground tobacco, 4 grams Example IV Ten parts of groundpolyvinyl acetate were mixed with 10 parts of ground polyethylene vinylacetate. This mixture was stirred with 1 part of triacetin and theresulting blend was mixed with 40 parts of tobacco dust. To this mixturewas added, with stirring, 4 parts of powdered sugar, 1 part of powderedlicorice and 1 part of black strap molasses.

The resulting powder was fed through four sets of rollers in successionwith the spacing of each set adjusted so as to have a clearance ofapproximately 0.003 inch. The product emerged from the last set as acontinuous ribbon with an average thickness of about 0.006 inch.

Liquid flavoring materials such as corn syrup, molasses, fruit extractand dry or solid flavoring materials such as powdered sugar and powderedlicorice, etc., may be added to the above mentioned compositions inamounts up to 20% of the weight of the tobacco used, providing only thatthey are not volatile and are not decomposed by heat below 100 C.

Operation of the apparatus and conduct of the process of this inventionwill be evident from the foregoing description thereof, whereby there isand may be produced a new chewing tobacco product which, when chewed, re

leases the tobacco taste and flavor from the individual tobaccoparticles, which, because of their relatively small size, expose andpresent a large aggregate surface area for soluble cooperation with thesaliva of the chewer. At the same time, the resin binder, beingchewable, holds the tobacco particles together in and as a plastic mass,whose plasticity increases with the warmth of the chewers mouth but doesnot become fluid so as to lose its plastic coherence.

The sheets, ribbons or rods-may be further subdivided and mixed withchewing leaf or used alone: and after being formed into cakes or plugs,small sheets, flakes, or other desired forms or shapes may be marketedin the usual way.

Although certain preferred proportions of tobacco fines to binder andflavoring components have been specified in the foregoing examples, itis to be understood that the invention is not limited thereby orthereto, but is susceptible of changes in form and detail within thescope of the appended claims.

We claim:

1. The method of forming a chewing tobacco product, which comprisesmixing tobacco particles with a waterinsoluble, odorless, tastelessthermoplastic binder having an adhesion temperature of less than C. andsoftenable to chewable plasticity at body temperature, compress ing saidmixture by forcing the same in an unheated condition through aconstricted space, to subject said mixture to pressure and friction togenerate sufficient heat to soften said thermoplastic binder and unitethe tobacco particles into a coherent non-self-sustaining rudimentarybody and further forcing said rudimentary body through at least oneother constricted space to generate sufficient heat to soften and rendersaid binder adherent and unite said tobacco particles into a coherentself-sustaining body.

2. The method of forming a self-sustaining body composed principallly oftobacco as set forth in claim 1 in which said binder is a thermoplasticpolymeric vinyl ester.

3. The method of forming a self-sustaining body composed principally oftobacco as set forth in claim 1 in which said binder is a thermoplasticpolyethylene vinyl acetate.

4. The method of forming a self-sustaining body composed principally oftobacco as set forth. in claim 1 in which said binder comprises amixture of a thermoplastic polyvinyl acetate and thermoplasticpolyethylene vinyl acetate.

5. The method of forming a self-sustaining body composed principally oftobacco as set forth in claim 1 in which said thermoplastic binder isdissolved in a non aqueous solvent, and said solvent is evaporated bythe heat generated by forcing said mixture through said constricted.spaces.

References Cited by the Examiner UNITED STATES PATENTS Re. 19,553 4/35Pfohl 18-12 551,306 12/95 Converse et al. 18-12 1,643,059 9/27 De Both264- 2,012,833 8/35 Smith 18-9 2,351,866 6/44 Miller 264-175 X 2,951,2639/60 Cooper 264-175 X 3,012,562 12/61 Merritt 131-140 3,025,860 3/62Grossteinbeck et al. 131-140 3,098,492 7/63 Wurzburg et a1 131-17 XABRAHAM G. STONE, Primary Examiner. P. RAY CHAPPELL, Examiner.

1. THE METHOD OF FORMING A CHEWING TOBACCO PRODUCT, WHICH COMPRISESMIXING TOBACCO PARTICLES WITH A WATERINSOLUBLE, ODORLESS, TASTELESSTHERMOPLASTIC BINDER HAVING AN ADHESION TEMPERATURE OF LESS THAN 100*C.AND SOFTENABLE TO CHEWABLE PLASTICITY AT BODY TEMPERATURE, COMPRESSINGSAID MIXTURE BY FORCING THE SAME IN AN UNHEATED CONDITION THROUGH ACONSTRICTED SPACE, TO SUBJECT SAID MIXTURE TO PRESSURE AND FRICTION TOGENERATE SUFFICIENT HEAT TO SOFTEN SAID THERMOPLASTIC BINDER AND UNITETHE TOBACCO PARTICLES INTO A COHERENT NON-SELF-SUSTAINING RUDIMENTARYBODY AND FURTHER FORCING SAID RUDIMENTARY BODY THROUGH AT LEAST ONEOTHER CONSTRICTED SPACE TO GENERATE SUFFICIENT HEAT TO SOFTEN AND RENDERSAID BINDER ADHERENT AND UNITE SAID TOBACCO PARTICLES INTO A COHERENTSELF-SUSTAINING BODY.